def math(o):
    if (o == 1):
        return lambda x, y: x + y
    if (o == 2):
        return lambda x, y: x + y
    if (o == 3):
        return lambda x, y: x * y
    if (o == 4):
        return lambda x, y: x / y


action = math(1)  # 返回加法Lambda表达式
print("10 + 2 = ", action(10, 2))
action = math(2)  # 返回减法Lambda表达式
print("10 - 2 = ", action(10, 2))
action = math(3)  # 返回乘法Lambda表达式
print("10 * 2 = ", action(10, 2))
action = math(4)  # 返回除法Lambda表达式
print("10 / 2 = ", action(10, 2))
